Genetic transformation has been an effective technology for improving the agronomic traits of maize.However,it is highly reliant on the use of embryonic callus(EC)and shows a serious genotype dependence.In this study,...Genetic transformation has been an effective technology for improving the agronomic traits of maize.However,it is highly reliant on the use of embryonic callus(EC)and shows a serious genotype dependence.In this study,we performed genomic sequencing for 80 core maize germplasms and constructed a high-density genomic variation map using our newly developed pipeline(MQ2Gpipe).Based on the induction rate of EC(REC),these inbred lines were categorized into three subpopulations.The low-REC germplasms displayed more abundant genetic diversity than the high-REC germplasms.By integrating a genome-wide selective signature screen and region-based association analysis,we revealed 95.23 Mb of selective regions and 43 REC-associated variants.These variants had phenotypic variance explained values ranging between 21.46 and 49.46%.In total,103 candidate genes were identified within the linkage disequilibrium regions of these REC-associated loci.These genes mainly participate in regulation of the cell cycle,regulation of cytokinesis,and other functions,among which MYB15 and EMB2745 were located within the previously reported QTL for EC induction.Numerous leaf area-associated variants with large effects were closely linked to several REC-related loci,implying a potential synergistic selection of REC and leaf size during modern maize breeding.展开更多
Food shortages arise more frequently owing to unpredictable crop yield losses caused by biotic and abiotic stresses. With advances in molecular biology and marker technology, a new era of molecular breeding has emerge...Food shortages arise more frequently owing to unpredictable crop yield losses caused by biotic and abiotic stresses. With advances in molecular biology and marker technology, a new era of molecular breeding has emerged that has greatly accelerated the pace of plant breeding. High-throughput genotyping technology and phenotyping platforms have enabled large-scale marker-trait association analysis, such as genome-wide association studies, to precisely dissect the genetic architecture of plant traits. Large-scale mapping of agronomically important quantitative trait loci, gene cloning and characterization, mining of elite alleles/haplotypes, exploitation of natural variations, and genomic selection have paved the way towards genomics-assisted breeding（GAB）. With the availability of more and more informative genomic datasets, GAB would become a promising technique to expedite the breeding cycle for crop improvement.展开更多
Root system architecture(RSA)contributes to nitrogen(N)uptake and utilization in maize.In this study,a germplasm enhancement of maize double haploid population of 226 lines genotyped with 61,634 SNPs was used to inves...Root system architecture(RSA)contributes to nitrogen(N)uptake and utilization in maize.In this study,a germplasm enhancement of maize double haploid population of 226 lines genotyped with 61,634 SNPs was used to investigate the genetic basis of RSA under two N levels using a genome-wide association study(GWAS).GLM+PCA,FarmCPU,and MLM models were utilized to balance false positives and false negatives.In total,33 and 51 significant SNP-trait associations were detected under high and low N conditions,respectively.Under high N,SNP S9_2483543 was detected by all models.Linkage disequilibrium(LD)regions of some SNPs overlapped with the intervals of QTL for RSA and N response that were detected in previous studies.In particular,several known genes,Rtcs,Rtcl,Rtcl,and Ms44,were located in the LD regions of S1_9992325,S9_151726472,S9_154381179,and S4_197073985,respectively.Among the candidate genes identified by this study,GRMZM2G139811,GRMZM2G314898,GRMZM2G054050,GRMZM2G173682,GRMZM2G470914,GRMZM2G462325,GRMZM2G416184,and GRMZM2G064302 were involved in seedling,seed,and root system development or N metabolism in Arabidopsis or rice.The markers identified in this study can be used for marker-assisted selection of RSA traits to improve nitrogen use efficiency in maize breeding,and the candidate genes will contribute to further understanding of the genetic basis of RSA under diverse N conditions.展开更多
Maximizing seed yield is the ultimate breeding goal in important cereal crop species. Seed set is a key developmental stage in the process of seed formation, which determines grain number, seed mass, and realized yiel...Maximizing seed yield is the ultimate breeding goal in important cereal crop species. Seed set is a key developmental stage in the process of seed formation, which determines grain number, seed mass, and realized yield potential, and can be severely affected by abiotic and biotic stresses. However, seed set can also be substantially reduced by genetic factors even under optimal fertilization conditions. The underlying molecular genetic mechanisms are still obscure. In this review, we elucidate the process of seed set of cereal crop species in detail, including development of floral structures, formation of viable gametes, double fertilization, seed development, and abortion. We discuss how genetic and non-genetic factors affect seed set in different development stages. Finally, we will propose novel strategies to study genetic mechanisms controlling seed set and exploit genetic resources to improve seed set in cereal crop species.展开更多
基金supported by the National Key Research and Development Program of China(2021YFF1000303)the National Nature Science Foundation of China(32072073,32001500,and 32101777)the Sichuan Science and Technology Program,China(2021JDTD0004 and 2021YJ0476)。
文摘Genetic transformation has been an effective technology for improving the agronomic traits of maize.However,it is highly reliant on the use of embryonic callus(EC)and shows a serious genotype dependence.In this study,we performed genomic sequencing for 80 core maize germplasms and constructed a high-density genomic variation map using our newly developed pipeline(MQ2Gpipe).Based on the induction rate of EC(REC),these inbred lines were categorized into three subpopulations.The low-REC germplasms displayed more abundant genetic diversity than the high-REC germplasms.By integrating a genome-wide selective signature screen and region-based association analysis,we revealed 95.23 Mb of selective regions and 43 REC-associated variants.These variants had phenotypic variance explained values ranging between 21.46 and 49.46%.In total,103 candidate genes were identified within the linkage disequilibrium regions of these REC-associated loci.These genes mainly participate in regulation of the cell cycle,regulation of cytokinesis,and other functions,among which MYB15 and EMB2745 were located within the previously reported QTL for EC induction.Numerous leaf area-associated variants with large effects were closely linked to several REC-related loci,implying a potential synergistic selection of REC and leaf size during modern maize breeding.
文摘Food shortages arise more frequently owing to unpredictable crop yield losses caused by biotic and abiotic stresses. With advances in molecular biology and marker technology, a new era of molecular breeding has emerged that has greatly accelerated the pace of plant breeding. High-throughput genotyping technology and phenotyping platforms have enabled large-scale marker-trait association analysis, such as genome-wide association studies, to precisely dissect the genetic architecture of plant traits. Large-scale mapping of agronomically important quantitative trait loci, gene cloning and characterization, mining of elite alleles/haplotypes, exploitation of natural variations, and genomic selection have paved the way towards genomics-assisted breeding（GAB）. With the availability of more and more informative genomic datasets, GAB would become a promising technique to expedite the breeding cycle for crop improvement.
基金China Scholarship Council(CSC)for Langlang Ma’s fundingUSDA’s National Institute of Food and Agriculture(IOW04314,IOW01018)+1 种基金Hatch Multistate Project NC-007the R.F.Baker Center for Plant Breeding at Iowa State University,for supporting this work.
文摘Root system architecture(RSA)contributes to nitrogen(N)uptake and utilization in maize.In this study,a germplasm enhancement of maize double haploid population of 226 lines genotyped with 61,634 SNPs was used to investigate the genetic basis of RSA under two N levels using a genome-wide association study(GWAS).GLM+PCA,FarmCPU,and MLM models were utilized to balance false positives and false negatives.In total,33 and 51 significant SNP-trait associations were detected under high and low N conditions,respectively.Under high N,SNP S9_2483543 was detected by all models.Linkage disequilibrium(LD)regions of some SNPs overlapped with the intervals of QTL for RSA and N response that were detected in previous studies.In particular,several known genes,Rtcs,Rtcl,Rtcl,and Ms44,were located in the LD regions of S1_9992325,S9_151726472,S9_154381179,and S4_197073985,respectively.Among the candidate genes identified by this study,GRMZM2G139811,GRMZM2G314898,GRMZM2G054050,GRMZM2G173682,GRMZM2G470914,GRMZM2G462325,GRMZM2G416184,and GRMZM2G064302 were involved in seedling,seed,and root system development or N metabolism in Arabidopsis or rice.The markers identified in this study can be used for marker-assisted selection of RSA traits to improve nitrogen use efficiency in maize breeding,and the candidate genes will contribute to further understanding of the genetic basis of RSA under diverse N conditions.
基金National Key Research and Development Program of China (2016YFD100103)the Major Science and Technology Projects in Henan Province, China (161100110500, 151100111000)+3 种基金the Science Foundation for the Excellent Youth Scholars of Henan Academy of Agricultural Sciences, China (2016YQ04)the International Cooperation Project in Henan Province, China (162102410034)USDA's National Institute of Food and Agriculture (IOW04314, IOW01018)the RF Baker Center for Plant Breeding and K. J. Frey Chair in Agronomy at Iowa State University for funding this work
文摘Maximizing seed yield is the ultimate breeding goal in important cereal crop species. Seed set is a key developmental stage in the process of seed formation, which determines grain number, seed mass, and realized yield potential, and can be severely affected by abiotic and biotic stresses. However, seed set can also be substantially reduced by genetic factors even under optimal fertilization conditions. The underlying molecular genetic mechanisms are still obscure. In this review, we elucidate the process of seed set of cereal crop species in detail, including development of floral structures, formation of viable gametes, double fertilization, seed development, and abortion. We discuss how genetic and non-genetic factors affect seed set in different development stages. Finally, we will propose novel strategies to study genetic mechanisms controlling seed set and exploit genetic resources to improve seed set in cereal crop species.
